The present invention relates to electric-contact posts for electrochemical machining tools.
These contacts, both on the electrode tools and the workpieces, pass high-intensity electric currents and the contact-resistance may be the source of considerable heating leading to destruction of the post and damage of the tool.
It has been attempted to limit such risks by reducing contact resistance to a minimum, notably by coating the contact surfaces of the post with a high-conductivity metal, such as silver, deposited electrolytically.
If these solutions improve the electrical contacts, they do not prevent accidental resistance which can arise because of impurities at the contact or poor condition of the workpiece surface reducing the area of contact.